Brendan Greaves says he originally wrote the number one hit Look Away, a power ballad performed by the band Chicago in the 1980s.
A British man is suing a prolific songwriter for $20m (£15m) in damages - and claims he was the true author of a song that reached number one in the US charts almost 30 years ago.
Brendan Greaves, from Yorkshire, says he invented Chicago's power ballad Look Away and not Diane Warren, who has written dozens of hits including Aerosmith's I Don't Want To Miss A Thing.
He alleges that he wrote the song when he was a 14-year-old student, and had submitted it to a British school music competition in 1987.
Mr Greaves did not win the contest sponsored by the now-defunct EMI Records, but claimed that Ms Warren acquired the tune through the contest.
Look Away topped the US singles chart in late 1988.
Mr Greaves has filed a lawsuit in a federal court in Los Angeles - and when asked why he had waited 30 years to complain, he said he lived in a "quiet village" in Yorkshire and had not heard the Chicago song until 2015.
A Twitter account believed to belong to Mr Greaves included a post published in May which alludes to the case.
"No matter how small or insignificant you think you are, keeping quiet is not the answer We all have a voice and there are good people in this world who will help make your voice louder. #neverlookaway #chicagolookaway #plagiarism #schoolkids #lowblow #perfectcrime #caughtintheact," it says.
A photo posted at the top of the Twitter account shows a cassette with the words "Look away by Brendan Greaves 2nd side" written on it.
Representatives for Ms Warren did not immediately comment.
A number of copyright lawsuits have been filed in recent years in the US.
Soul legend Marvin Gaye's estate won $5.3m (£4m) after claiming that singer and songwriter Robin Thicke's track Blurred Lines was stolen from the soul legend's song Got To Give It Up.
Singer-songwriter Ed Sheeran reached a settlement with writers Thomas Leonard and Martin Harrington over the singer's song Photograph.
The pair had argued Mr Sheeran copied the track "note for note".
© Sky News 2018